Can Steam ban you for this?
Can Steam ban you for this?
They can view all logs, just like the PMs here. If someone mentions another during a chat, staff will check that conversation. Sending messages too quickly might lead to temporary bans for most users. Pure text spam isn't likely to cause such penalties—it's more of an annoyance than a real threat.
I suppose it's possible. Technically Valve "can" ban you from their service for whatever they arbitrarily decide is worthy of a ban. I think you're likely fine in this case, though. If you were spamming with a bot they may do something, but there is a limit to how many "w's" a human hand/attention span can send consecutively. Maybe don't spam people with private messages. You could've reported, blocked, and gotten on with your life, with a little more dignity left and—bonus!—it would've actually been the lazier and safer option as well. It would have been just as effective, possibly more so.